(19)

(11)

EP 3 997 893 A1

(12)

(43) Date of publication: 18.05.2022 Bulletin 2022/20 (21) Application number: 20743603.1 (22) Date of filing: 13.07.2020

(51) International Patent Classification (IPC):  H04R 7/12(2006.01) C23C 16/27(2006.01) H04R 31/00(2006.01) (52) Cooperative Patent Classification (CPC): C23C 16/01; C23C 16/274; H04R 7/127; H04R 31/003; H04R 2207/021; H04R 2307/023 (86) International application number: PCT/EP2020/069781 (87) International publication number: WO 2021/009133 (21.01.2021 Gazette 2021/03)

(84) Designated Contracting States: AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR Designated Extension States: BA ME Designated Validation States: KH MA MD TN (30) Priority: 12.07.2019 US 201962873366 P 02.08.2019 GB 201911086 (71) Applicant: Element Six Technologies Limited Didcot, Oxfordshire OX11 0QR (GB)

(72) Inventors: WICKHAM, Benjamin Oxford Didcot Oxfordshire OX11 0QR (GB) BRANDON, John Robert Oxford Didcot Oxfordshire OX11 0QR (GB) NASSER-FAILI, Firooz Santa Clara, California 95054 (US) O'MALLEY, Dermot Francis Oxford Didcot Oxfordshire OX11 0QR (GB) (74) Representative: Mitchell, Matthew Benedict David et al Element Six Limited Group Intellectual Property Fermi Avenue Harwell Campus Didcot, Oxon OX11 0QR Didcot, Oxon OX11 0QR (GB)